1. Field of the Invention
The present invention relates to an automated system for controlling the incineration of solid wastes in an excrement disposal system.
2. Description of the Prior Art
Boats, motor homes, campers and other recreational vehicles have long been provided with toilets which the occupants of such vehicles utilize for the disposal of bodily wastes.
For many years, boats and yachts were constructed with toilets in which wastes were discharged directly into the sea. In such systems sea water was pumped from outside the vessel through the raw waste deposit container, typically a toilet bowl, and back out through a discharge outlet into the sea. In this manner sea water was pumped, either manually, or with the assistance of an electric motor, through a series of one way valves that discharged excrement and other wastes directly into the sea as raw sewage. Due to the vast volume of sea water this was considered to be an acceptable practice for quite some time. However, with the increased numbers of pleasure craft which began to crowd into desireable harbor and mooring areas, the discharge of raw sewage into the sea became unacceptable in waste disposal systems.
Other alternative toilet systems were devised for use on boats and other recreational vehicles. One type of system involves the use of a portable toilet, in which at least the initial receptacle for receiving unprocessed raw waste may be detached from beneath the toilet seat and emptied periodically into conventional toilets, or other sewage receptacles, which flow into municipal sewage systems. However, this type of portable toilet has a number of disadvantages. Because the raw waste cannot be emptied until an appropriate waste discharge facility is available, excrement must remain in portable toilets, sometimes for lengthy periods of time. Because the excrement reception containers must be removable, they are not air tight. Therefore, unpleasant odors from the raw waste receptacle tend to permeate the vessel or vehicle in which portable toilets are utilized. Chemicals are available to mask the smell, but they typically have their own unpleasant odors and must be stored where storage space is at a premium.
Other types of toilets for boats and other recreational vehicles operate on a pump-out system. That is, the vehicle or vessel must be taken to a specialized pump-out facility where tubes are connected to a flushing system to carry rinsing water into the waste receptacle of the onboard toilet, and from the waste receptacle into a municipal sewage discharge system. An onboard pump-out type toilet has one advantage in that since the waste receptacle is not removed, it can be made relatively air tight. Consequently, unpleasant odors are less of a problem.
However, a pump-out toilet system has significant disadvantages in that large quantities of water are required to adequately entrain and carry the excrement material from the onboard receptacle into the municipal sewage system. This places a considerable demand on the requirements for fresh water at such installations. Also, since the pump out stations are of such a specialized nature, they are expensive to construct and are not always readily available.
Another waste management system which has been devised involves the onboard incineration of excrement materials in a toilet system located on a boat or other recreational vehicle. Such a system requires bottled, combustible gas and an incineration chamber. A slurry of entrained wastes is sprayed into the incineration chamber in which a jet of gas is burning. The high heat of the burning gas quickly evaporates the water entraining the solid waste material and incinerates the solid waste material itself, leaving nothing but a small quantity of incinerated ash. One such system is described in U.S. Pat. No. 3,912,598.
While conventional onboard waste incineration systems can perform their intended function, the controls for such systems involve the manual manipulation of valves and the lighting of burners which require a thorough knowledge of the manner of operation of the system. Also, unless the valves and burners are operated in precisely the correct sequence and for a proper duration, a conventional, onboard excrement incineration system can malfunction, thereby causing sewage overflows, clogging of lines, damage from excessive incineration temperatures, and other problems in the system. Moreover, these problems can occur even if an individual thoroughly familiar with the system tends to its operation. These problems are due to changes in the duration and frequency of valve and burner operation which occur with varying volumes of waste to be processed and due to varying volume levels in the various tanks.